This disclosure relates generally to a print on demand (POD) book printing and binding apparatus, such as shown in our co-pending U.S. patent application Ser. No. 12/576,923, filed Oct. 9, 2009, which is herein incorporated by reference in its entirety. In this apparatus for print on demand book manufacture, it is typical that a laser duplex page printer prints the text pages of the book on sheets of paper with one text page printed on each face of each sheet. After printing, the sheets are conveyed from the printer to an accumulator where they are accumulated to form a book block. As part of the printing process, the sheets are heated during the printing process to an elevated temperature so as to fuse the printer toner to the sheets. Because the sheets are rapidly conveyed from the printer to the accumulator remain at an elevated temperature (compared to ambient temperature) as they are accumulated in the stack or book block. Of course, because of the thermal mass of the book block the sheets in the book block remain at an elevated temperature for a matter of minutes. Oftentimes, prior to the sheets being stacked in the accumulator, the sheets are passed through a de-curling device, as indicated by reference character 13 in the above-noted U.S. patent application Ser. No. 12/576,923, so as to de-curl or flatten the sheets prior to accumulating them in an accumulator to form a book block or the like. However, the sheets pass through the de-curler so fast that little cooling takes place in the de-curler, particularly after the apparatus has come up to its normal operating temperature. Of course, the flatter the sheets are before they are stacked to form the book block, the flatter the book block and the book to be formed from the book block.
Further, when sheets are printed by such a laser printer and discharged therefrom, the sheets carry an electrostatic charge. As is known, such electrostatic charge on the sheets interferes with the uniform stacking of the sheets to form the book block or other document.
In the manufacture of such POD printing and binding apparatus, it is oftentimes necessary or desirable to utilize page printers of different manufacturers or different models of printers. Oftentimes, these printers have a sheet discharge at a different height so that it is problematic of how to adjust the height of the infeed of the POD apparatus and the discharge of the printer.